Field of the Invention
The present invention relates to a lifting vehicle comprising:
a frame carrying a front axle and a rear axle, carrying a pair of front wheels and a pair of rear wheels, respectively;
a lifting arm articulated in a rear section of the frame; and
a stability control system configured to control the conditions of operational stability of the vehicle.
Description of Prior Art
The reference legislation for stability control systems of lifting vehicles is the regulation EN15000. One of the main security features provided by the regulation EN15000 for vehicles with lifting arms is the control function of the risk of longitudinal rollover. To perform this safety function, micro-switches arranged on the rear axle are used, which detect when the rear axle load falls below a predetermined threshold. An electronic control unit alerts the operator to a situation of the risk of rollover and blocks the movements that aggravate the rollover risk.
The document EP-A-2520536 by the same Applicant describes a lifting vehicle equipped with a stability control system including an electronic control unit that receives information provided by: a length sensor, which detects the length of extension of the arm; an angle sensor, which detects the inclination angle of the telescopic arm, and by sensors that provide information on the type of equipment applied to the arm. The electronic control unit is programmed to act on a limiting valve in order to limit the maximum speed of lowering the arm depending on the type of equipment, the value of the load applied to the arm, and the length and angle of inclination of the arm.
The information on the type of equipment mounted on the arm, together with the information gathered from the various control sensors of the arm geometry and load weighing sensors carried by the arm allow the correct stability diagram to be provided to the operator, along with continuous information in real time on the instantaneous stability conditions of the vehicle.
However, this stability control system and those of lifting vehicles currently available on the market are configured to check only the longitudinal stability of the vehicle, or rather, the degree of stability against the risk of longitudinal rollover.
On the other hand, for the operational safety of lifting vehicles, transverse stability is also very important, especially in the case of vehicles that can also operate on uneven and rough terrains, such as some vehicles with lifting arms that are also usable as agricultural tractors. In fact, the transverse rollover is one of the most serious accidents with respect to agricultural vehicles.